Direct, an advertising agency in South Africa, made this ad for Douwe Egberts, a company that manufactures coffeemakers. Direct built a coffee vending machine and placed it in the O.R. Tambo International Airport outside of Johannesburg, South Africa. The machine had no obvious interface—no means of placing an order or inserting money.

It did, however, have a camera and facial recognition software in its computer. When the machine detected someone in front of it yawning, it dispensed a free cup of coffee. In the video below, watch sleepy passengers react with surprise, like the machine is reading their minds.